Image sensor with inter-pixel isolation

Abstract

An image sensor with a plurality of photodiodes that each have a first region constructed from a first type of material and a second region constructed from a second type of material. The photodiodes also have an insulating region between the first and second regions. The photodiodes are arranged in an array. In corner regions of the array, the second regions are offset relative to the insulating regions to capture more photons of incoming light.

1 . An image sensor, comprising:
 a pixel array that includes a plurality of photodiodes, said photodiodes in a corner area of said pixel array each include;
 a first region constructed from a first type of material; 
 an insulating region adjacent to said first region; and, 
 a second region that is constructed from a second type of material and is offset from said insulating region. 
   
   
   
       2 . The image sensor of  claim 1 , further comprising a barrier region that is constructed from said first type of material, and located beneath said first region and between second regions of adjacent photodiodes, said barrier region being offset from said first region for photodiodes in said corner area. 
   
   
       3 . The image sensor of  claim 1 , wherein said first type of material is a p-type material and said second type of material is an n-type material. 
   
   
       4 . The image sensor of  claim 1 , wherein said second region is offset by 0.5 μm. 
   
   
       5 . A method for forming a plurality of photodiodes of an image sensor, comprising:
 forming a first region;   forming an insulating region adjacent to the first region; and,   forming a second region that is offset from the insulating region.   
   
   
       6 . The method of  claim 5  further comprising forming a barrier region that is offset from the first region. 
   
   
       7 . The method of  claim 5 , wherein the second region is offset by 0.5 μm. 
   
   
       8 . The method of  claim 5 , wherein the first type of material is a p-type material and the second type of material is an n-type material.